From our vantage point in the soil, the difference is a matter of life and death. When overwatered, we roots are constantly submerged. The air pockets in the soil fill with water, and we literally begin to drown. We cannot breathe, and without oxygen, we start to rot, turning soft, mushy, and dark brown. This rot prevents us from absorbing any water or nutrients at all, creating a cruel irony. Conversely, when underwatered, we become desperate. The soil pulls away from the edges of the pot, and we are left straining in a dry, hardened environment. We become brittle and thin, sometimes shriveling in a last-ditch effort to conserve the plant's minimal moisture. We are not dead, but we are dormant and thirsty, waiting for a drink to revive us.
Our stems act as the plant's structural support and plumbing system. Under the stress of overwatering, we become weak and soft. The cells, damaged by the lack of oxygen and the onset of root rot, cannot maintain their turgor pressure. We may feel limp, mushy, and even appear darker or blackened near the base. This is a sign of advanced decay. In contrast, the stems of an underwatered sage plant tell a story of drought. We become woody, brittle, and may even crack. We wilt not because we are rotting, but because we have no water to hold us upright. The entire structure feels dry and lifeless to the touch, lacking any suppleness.
We leaves are the most visible communicators of the plant's distress. When overwatered, we often turn a universal yellow, particularly the older leaves near the base. This yellowing is a slow, chlorotic fade, often accompanied by a soft, pulpy texture. We may droop limply and feel cool and waterlogged. We might even develop oedema, where our cells burst from excess water, creating blister-like patches. When underwatered, our message is far more dramatic and crisp. We become dry, brittle, and curl inward at the edges to reduce surface area and minimize water loss. Our color changes from a healthy grey-green to a dull, dusty grey or brown. We do not simply droop; we become crispy and crumble easily when touched, a clear and desperate plea for hydration.
Observing the entire plant reveals the core narrative. An overwatered sage exhibits a general sogginess and stagnation. There is no new growth, or any new shoots that do appear may be stunted and weak. The plant smells damp and unhealthy, a direct result of the rotting roots below the soil. The decline is often slow and pervasive. An underwatered sage, however, portrays severe dehydration. Growth is also halted, but the plant feels dry to its core. The soil will be dusty and pulled away from the pot. The plant might appear to be conserving every last drop of moisture, with all its parts—stems, leaves, and even the soil—crying out for water in a unified, parched state.
